Measurement Guide
IN020 Rev X 0218 43 Saber Way, Ward Hill, MA 01835 | radonaway.com
1.7 CONDENSATION & DRAINAGE
Condensation is formed in the piping of a mitigation system when the air in the piping is chilled below its dew point.
This can occur at points where the system piping goes through unheated space such as an attic, garage or outside.
The system design must provide a means for water to drain back to a slab hole to remove the condensation. The RP /
RPc Series Fan MUST be mounted vertically plumb and level, with the outlet pointing up for proper drainage through
the fan. Avoid mounting the fan in any orientation that will allow water to accumulate inside the fan housing. The RP
/ RPc Series Fans are NOT suitable for underground burial.
For RP / RPc Series Fan piping, the following table provides the minimum recommended pipe diameter and pitch
under several system conditions.
*Typical RP/RPc (except RP380/RP380c) Series Fan operational ow rate is 25 - 90 CFM on 3” and 4” pipe.(For more precision,
determine ow rate by measuring Static Pressure, in WC, and correlate pressure to ow in the performance chart in the addendum.)
Pipe
Diameter
Minimum Rise per Ft of Run*
@25 CFM @50 CFM @100 CFM @200 CFM @300 CFM
6” - 3/16 1/4 3/8 3/4
4” 1/8 1/4 3/8 2 3/8 -
3” 1/4 3/8 1 1/2 - -
1.8 SYSTEM MONITOR & LABEL
A System Monitor, such as a manometer (P/N 50017) or audible alarm (P/N 28001-2, 28001-4 or 28421),
should be provided and is required to notify the occupants of a fan system malfunction. A System Label (provided
with Manometer P/N 50017) with instructions for contacting the installing contractor for service and identifying
the necessity for regular radon tests to be conducted by the building occupants must be conspicuously placed in a
location where the occupants frequent and can see the label.
1.9 VENTILATION
If used as a ventilation fan, any type of ducting is acceptable; however, exible nonmetallic ducting is recommended
for easy installation and quieter operation. Insulated exible ducting is highly recommended in cold climates to
prevent the warm bathroom air, for example, from forming condensation in the ducting where it is exposed to colder
attic air. The outlet of the fan should always be ducted to the outside. Avoid venting the outlet of the fan directly into
an attic area. The excess moisture from the bathroom can cause damage to building structure and any items stored
in the attic. Multiple venting points may be connected together using a “T” or “Y” tting. Ideally, the duct should
be arranged such that equal duct lengths are used between intake and “T” or “Y” tting; this will result in equal
ow rates in each intake branch. If adjustable intake grilles are used on multi-intake systems, then the opening on
each grille should be equal in order to minimize noise and resistance. Straight smooth runs of rigid metal ducting
will present the least resistance and maximize system performance. The Equivalent Length of Rigid Metal Ducting
resulting in .2”WC pressure loss for each Fan Model is provided in the Specications section of these instructions.
Flexible ducting, if used, must always be as close to being fully extended as possible. Formed rigid metal duct elbows
will present the least resistance and maximize system performance; recommended bend radius of elbow is at least
1.5 x duct diameter.
RP / RPc Series fans are not suitable for kitchen range hood remote ventilation applications. For quietest performance,
the fan should be mounted farther away from the inlet duct, near the outside vent. A minimum distance of 8 feet is
recommended between the fan or T/Y of a multi-intake system and intake grille(s).
Backdraft dampers allow airow in only one direction, preventing cold/hot draughts from entering the vented area
and minimizing possible condensation and icing within the system while the fan is not operating. Backdraft dampers
are highly recommended at each intake grille for bathroom ventilation in all cold climate installations. Installation
instructions are included with Spruce backdraft dampers.